Filtering cardiotomy reservoir

ABSTRACT

A surgical blood sucker and peristaltic pump combination discharge a three-phase mixed stream of blood, air and surgical tissue debris into a cardiotomy reservoir through a slot shape blood inlet nozzle tangentially disposed on the wall of the blood reservoir volume. The tissue debris is collected internally in the reservoir on the reservoir base filter face and the face of the conical air filter. The air, under slight pressure in the reservoir, exits from the reservoir through the air filter and a relief valve. The defoamed blood flows from the reservoir through multiple base filter plate exit apertures, into a blood oxygenator.

United States Patent [191 Brumfield Oct. 30, 1973 FILTERING CARDIOTOMYRESERVOIR [76] Inventor: Robert C. Brumfield, 73 Emerald Bay, LagunaBeach, Calif. 92657 [22] Filed: Mar. 21, 1972 211 App]. No.: 222,124

[56] References Cited UNITED STATES PATENTS 2,833,279 5/1958 Gollan23/258.5

Primary ExaminerFrank A. Spear, Jr. Attorney-J. L. Jones [57] ABSTRACT Asurgical blood sucker and peristaltic pump combination discharge athree-phase mixed stream of blood, air and surgical tissue debris into acardiotomy reservoir through a slot shape blood inlet nozzletangentially disposed on the wall of the blood reservoir volume. Thetissue debris is collected internally in the reservoir on the reservoirbase filter face and the face of the conical air filter. The air, underslight pressure in the reservoir, exits from the reservoir through theair filter and a relief valve. The defoamed blood flo'ws from thereservoir through multiple base filter plate exit apertures, into ablood oxygenator.

1 FILTERING CARDIOTOMY RESERVOIR CROSS-REFERENCES TO RELATED APPLICATIONThis application is related to the following applications filed earlierby the same sole inventor:

US. Pat. application, Ser. No. l75,l82 for BLOOD OXYGENATOR ANDTHERMOREGULATOR AP- PARATUS by Robert C. Brumfield, filed Aug. 26, I971;

US. Pat. application, Ser. No. l96,458, for BLOOD OXYGENATOR GLOW GUIDE,by Robert C. Brumfield, filed Nov. II, 1971;

US. Pat. application Ser. No. 202779 FOR BLOOD OXYGENATOR, by Robert C.Brumfield, filed Nov. 29, 1971; and

US. Pat application Ser. No. 216,649 for LOW PRESSURE HEAT EXCHANGER FOROXYGEN- ATED BLOOD, by Robert C. Brumfield, filed .Ian. 10, 1972.

BACKGROUND OF THE INVENTION Blood oxygenators useful for oxygenatingpatients blood during extra-corporeal circulation are classified inClass 23 Subclass 258.3. The cardiotomy reservoir of this invention istaught to be useful in combination with a blood oxygenator, and theinvention is so classitied.

Often there is a substantial loss of patient blood during surgicaltreatment, and surgical blood suckers are useful for processing andreturning blood to the patients extra-corporeal circulation. Since therecovered blood can contain surgical tissue debris, the blood canrespond to the debris by initiating the clotting mechanism. It isdesirable to remove the debris from the recovered blood as quickly aspossible prior to returning this blood to the patient. The cardiotomyreservoir of this invention quickly and cleanly processes patient blood,filtering the surgical debris and simultaneously defoaming the blood forrapid return to the patients circulation.

SUMMARY OF THE INVENTION A cardiotomy reservoir for recovering patientsblood in a surgical procedure has a uniform tubular case having a baseplate and a top plate, together providing an enclosed reservoir volume.A blood inlet conduit is secured in the reservoir providing a slotaperture discharge nozzle directing a flat blood inlet stream flowtangentially onto the inside tubular wall of the reservoir. The smallcentrifugal force of the blood stream flow tends to deposit the surgicaltissue debris on the tubular wall. A reservoir base filter iscoextensive with the base plate and has a porosity suitable forfiltering whole blood, yet retaining surgical tissue debris on the basefilter inside the receptacle. A retaining ring means coplanarly securesthe reservoir base filter to the reservoir base plate. An air filter isconcentrically coextensive with the tubular case, from the top plate ofthe reservoir to the base filter, the air filter having a porositysuitable for filtering air, yet blocking blood flow through it. An airexit conduit is normally centrally disposed from the reservoir topplate, discharging filtered air from the reservoir. A plurality of bloodexit apertures conductively disposed through the base plate provide forflow of filtered blood from the cardiotomy reservoir. The reservoir basefilter and the air filter are both treated with a very thin film of adefoaming composition which is physiologically compatible with patientblood, thereby facilitating the defoaming of the blood, air and surgicaltissue debris as it is pumped into the cardiotomy reservoir. A slightinternal reservoir positive pressure ranging up to lOO mm Hg maintains apositive flow of blood out of the cardiotomy reservoir through the baseplate blood exit apertures. The positive pressure is maintained insidethe cardiotomy reservoir by a low pressure release valve secured to theair exit conduit. The air filter can be truncated cone shaped porousfilter having a cone apex centrally disposed adjacent the reservoir basefilter and a cone base disposed adjacent the top plate of the reservoir.The reservoir base filter and the air filter can be porous reticulatedpolyurethane foam or a porous silicone foam of selected porosity. Theair filter is typically a foam having 10. pores per lineal inch. Thereservoir base filter typically passes particle sized to microns.

Other objects and advantages of this invention are taught in thefollowing description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS A description of this invention is tobe read in conjunction with the following drawings:

FIG. 1 is an elevational perspective partial sectional view of thecardiotomy reservoir of this invention, disposed in a blood oxygenator.

FIG. 2 is a sectional view through 2-2 of FIG. 1.

FIG. 3 is a sectional view disclosing a further modification of thisinvention similar to the view of FIG. 2.

FIG. 4 is another sectional view through 44 of FIG. 1.

FIG. 5 is a detailed perspective fragmentary view illustrating the baseplate 13 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT A surgical blood sucker and aperistaltic pump combination are used to suck up blood lost in asurgical procedure or the like. The sucker and pump combinationdischarge a three-phase mixture of blood, air and surgical tissue debrisinto the cardiotomy reservoir.

Referring to FIG. 1 in detail, the cardiotomy reservoir 10 of thisinvention is shown disposed in the top portion of the blood oxygenator11. The cardiotomy reservoir 10 has a uniform receptacle tubular case 12closed by a base plate 13 and a top plate 14, providing an enclosedreservoir volume 15. A blood inlet conduit 16 is normally securedthrough the top plate 14, and has a blood inlet conduit discharge nozzle34, whose slot discharge aperture 17 is permanently positioned,directing a flat blood inlet stream flow tangential to the inner wall 18of the case 12. A reservoir base filter 19 is coextensive with the baseplate 13, the filter 19 providing a porosity suitable for filteringwhole blood. Typically the filter 19 has pore openings sized to pass 100micron size particles, and retain surgical tissue debris inside thereservoir volume 15 on the base filter 19. A retaining ring 20 securesthe filter 19 on the base plate 13. The ring 20 is sealed to the tubularcase ring 30, which is in turn sealed to the base plate 13. The tubularcase 12 is sealed to the ring 30 and the top plate 14, providing anintegral structure.

An air filter 21 is shown concentrically conextensively disposed in thereservoir 10, coextending from the top plate 14 to the base filter 19.The truncated cone 21 has a truncated apex 22 and a cone base 23. Theair filter 21 is a plastic sponge having a porosity suitable forfiltering air yet blocking blood flow. An air exit conduit 24 isnormally centrally disposed through the top plate 14 providing an exitconduit discharging filtered air from the reservoir volume 15.Typically, the conduit 24 is sealed to the top plate 14. A pressurerelief valve 25 is shown conductively disposed on the conduit 24, therelief valve being set to relieve at a pressure approximately 100 mm Hgabove atmospheric pressure. A plurality of blood exit apertures 26 areconductively disposed through the base plate 13, providing for the flowof filtered blood from the cardiotomy reservoir 10. The filtercomponents, the air filter 21 and the reservoir base filter 19 are bothcoated by well known procedures with physiological compatiblecompositions which accelerate blood defoaming on contact with the filmcoating. Typically, a silicone composition is well known and used forthis purpose. Plural base filter leaf supports 27 are shown coplanarlyintegrally secured to the base plate 13, providing blood exit flowrelieving passage means for the blood filtered through the filter 19.

The reservoir is shown disposed in the top of an oxygenator 11, of thepreviously cited inventions of this inventor. The blood inlet conduit16' and the air outlet conduit 24 are sealed through the oxygenator top35 by the conventional O-ring seal combinations 36 and 37. The oxygengas exit conduit 38 releases the gas stream 33 from the oxygenator 11.

FIG. 2 illustrates in detail through the cross sectional view through 22of FIG. 1, that the nozzle 34 having a slot discharge aperture 17 of theblood inlet conduit 16 is tangentially disposed to the internal wall 18of the reservoir volume formed by the wall 12. Thus, blood mixture 31pumped into the cardiotomy reservoir 10 through the narrow slot aperture17 is spread in a flat blood inlet stream flow tangentially over thewall 18 tending to distribute the surgical tissue debris pumped into thecardiotomy reservoir over a large wall area. The debris is retained onthe reservoir base filter 19 and on the air filter 21, as the foamedblood 28 is defoamed on contact with the two filters 19 and 21. Thecurved nozzle 34 represents another wall curvature conforming tangentialnozzle.

In surgical procedures the cardiotomy reservoir 10 operates at pressuresabove atmospheric, resulting from the pump pressurized discharge ofblood, air and surgical tissue debris into the reservoir 10. The reliefvalve 25 allows escape of the air stream 32 at the set relief pressureof the valve 25, which can typically be 100 mm Hg.

A further modification of the blood inlet nozzle is shown in FIG. 3, ina cross sectional view similar to 2--2 of FIG. 1. The cardiotomyreservoir 10" is disposed in a blood oxygenator 11. In the reservoirmodification 10, the blood inlet conduit 16 has a nozzle 34" integrallytangentially disposed on the exterior wall of the tubular case 12",providing a slot aperture 17" disposed in the case 12". The base 23 ofthe air filter 21 is shown disposed, as in FIG. 2.

Referring to FIG. 4 in detail, the base plate 13 is shown in twomodifications separated by a diametrical line 41. The plurality of bloodexit apertures 26 are shown conductively disposed through the base plate13 providing for the flow of filtered blood from the cardiotomyreservoir under slight pressure. The plural base filter leaf supports 27are shown coplanarly integrally secured on the plate 13, providingrecesses between the leaf supports 27 for the channel flow of filteredblood from the superimposed reservoir base filter 19. On the other halfof the filter plate 13 separated by the diametrical line 41 is shown aplurality of blood exit apertures 26' which also are conductivelydisposed through the base plate 13'. A circular recess channel 42 formedin the base plate 13' has a plurality of blood exit recess channels 40leading from the circular recess channel 42 to the blood exit apertures26'. Thus in principle, the base plate 13 and the modified base plate13' can have the blood flow relieving passage means 27, or the meanscomprising 42 plus 40 disposed in the filter plate 13. Each blood flowrelieving passage means 27, or the like, provides for the flow of bloodfrom the cardiotomy reservoir typically into the defoaming chamber, orthe like, of a blood oxygenator.

Typically, the cardiotomy reservoir 10 disposed in the blood oxygenator11, as shown in FIG. 1, is mounted on the top of a tubular array 43 inthe recessed aperture 44 providing for the support of the reservoir 10.The tubular array 43, including its various modifications, are disclosedin the above crossreferenced patent applications of this inventor.

This invention provides a cardiotomy reservoir which quickly processes athree-phase mixture of blood, air and surgical tissue debris providingrapid removal of tissue debris from the blood, together with promptdefoaming of the blood, thus allowing the treated blood to be returnedto a patients extra-corporeal circulation. By the prompt treatment andreturn of the blood to circulation, the potential for initiating bloodclotting is reduced, hence the post operative prognosis is en hanced.

Many modifications and variations in the improvement in a cardiotomyreservoir can be made in the light of my teaching. It is thereforeunderstood that within the scope of the appended claims, this inventionmay be practiced otherwise than as specifically described.

I claim:

1. A cardiotomy reservoir for recovering patient blood in a surgicalprocedure, comprising in combination: I I

a uniform tubular case having a base plate and a top plate, providing anenclosed reservoir volume;

a blood inlet conduit secured through the reservoir wall adjacent thesaid top plate, said conduit having a nozzle having an oriented slotdischarge aperture providing a flat blood inlet stream flow tangentiallyon the inner tubular wall of said case;

a reservoir base filter coextensive with said base plate, said filterhaving a porosity suitable for filtering whole blood, said filterretaining surgical tissue debris inside said receptacle on the filterface;

a retaining ring means coplanarly securing said reservoir base filter tosaid base plate;

an air filter concentrically coextending in said tubular receptacle fromsaid top plate to said base filter, said air filter having a porositysuitable for filtering air and blocking blood flow;

an air exit conduit normally centrally disposed through said top plate,said exit conduit discharging filtered air from said reservoir;

a plurality of blood exit apertures conductively disposed through saidbase plate, providing for the flow of filtered blood from saidcardiotomy reservoir; and,

all aforesaid components physiologically compatible with patient blood.

2. The combination of claim 1 wherein the blood inlet conduit comprises:

a blood inlet conduit normally secured through said top plate adjacentthe top plate perimeter and the receptacle wall, said conduit having anozzle having an oriented slot discharge aperture providing a fiat inletstream flow tangentially on the inner tubular wall of said receptacle.

3. The combination of claim 1 wherein the base plate comprises:

a plurality of blood flow relieving passage means disposed in the faceof base plate adjacent said reservoir base filter.

4. The combination of claim 1 wherein said reservoir base filtercomprises:

a porous reticulated polyurethane foam having a porosity passing bloodelements ranging up to 100 microns diameter, said foam coated with afilm composition collapsing blood-air foam.

5. The combination of claim 1 wherein said reservoir base filtercomprises:

a porous silicone foam having a porosity ranging up to 100 microndiameter, said silicone foam collapsing blood-air foam.

6. The combination of claim 1 wherein said reservoir air outlet conduithas a pressure relief valve secured thereon, said valve relieving at apressure not exceeding 100 mm Hg above atmospheric.

7. The combination of Claim 1 wherein said air filter comprises:

a truncated cone shape porous filter having a truncated cone apexcentrally disposed adjacent said reservoir base filter and a cone basedisposed adjacent said top plate.

8. The combination of claim 7 wherein said truncated cone shape porousfilter comprises:

a porous reticulated polyurethane foam having a porosity ranging up from10 pores per lineal inch, said foam coated with an air-blood foamcollapsing composition.

9. The combination of claim 7 wherein said truncated cone shape porousfilter comprises:

a porous silicone foam structure having a porosity ranging up from 10pores per lineal inch.

10. In a cardiotomy reservoir whose internal reservoir volume isenclosed by a reservoir case having a case top and case base, thecombination comprising:

a blood inlet conduit secured through the reservoir wall adjacent saidcase top, said conduit having a nozzle having an oriented dischargeaperture providing a blood inlet stream flow tangentially on the innerwall of said case;

a reservoir base filter coextensive with said case base, said filterhaving a porosity suitable for filtering whole blood, said filterretaining surgical tissue debris inside said case on the filter face;

a means coplanarly securing said reservoir base filter to said casebase;

an air filter concentrically coextending in said reservoir case fromsaid case top to said base filter, said air filter having a porositysuitable for filtering air and blocking blood flow;

an air exit conduit normally centrally disposed through said case top,said exit conduit discharging filtered air from said reservoir volume;

a plurality of blood exit apertures conductively disposed through saidcase base, providing for the flow of filtered blood from said cardiotomyreservoir;

and,

all aforesaid components physiologically compatible with patient blood.

11. The combination of claim 10 wherein the nozzle of the blood inletconduit has a slot aperture providing a flat oriented blood inlet flowtangentially on the inner wall of said case.

12. The combination of claim 10 wherein the blood inlet conduitcomprises: I

a blood inlet conduit normally secured through said case top adjacentthe case top perimeter and the case wall, said conduit having a nozzlehaving an oriented slot discharge aperture providing a flat inlet streamflow tangentially on the inner tubular wall of said receptacle.

13. The combination of claim 10 wherein the case base comprises:

a plurality of blood flow relieving passage means disposed in the faceof case base adjacent said reservoir base filter.

14. The combination of claim 10 wherein said reservoir base filtercomprises:

a porous reticulated polyurethane foam having a porosity passing bloodelements ranging up to microns diameter, said foam coated with a filmcomposition collapsing blood-air foam.

15. The combination of claim 10 wherein said reservoir base filtercomprises:

a porous silicone foam having a porosity ranging up to 100 microndiameter, said silicone foam collapsing blood-air foam.

16. The combination of claim 10 wherein said reservoir air outletconduit has a pressure relief valve secured thereon, said valverelieving at a pressure not exceeding 100 mm Hg above atmospheric.

17. The combination of claim 10 wherein saidair filter comprises:

a truncated cone shape porous filter having a truncated cone apexcentrally disposed adjacent said reservoir base filter and a cone basedisposed adjacent said top plate.

18. The combination of claim 17 wherein said truncated cone shape porousfilter comprises:

a porous reticulated polyurethane foam having a porosity ranging up from10 pores per lineal inch, said foam coated with an air-blood foamcollapsing composition.

19. The combination of claim 17 wherein said truncated cone shape porousfilter comprises:

a porous silicone foam structure having a porosity ranging up from 10pores per lineal inch.

1. A cardiotomy reservoir for recovering patient blood in a surgicalprocedure, comprising in combination: a uniform tubular case having abase plate and a top plate, providing an enclosed reservoir volume; ablood inlet conduit secured through the reservoir wall adjacent the saidtop plate, said conduit having a nozzle having an oriented slotdischarge aperture providing a flat blood inlet stream flow tangentiallyon the inner tubular wall of said case; a reservoir base filtercoextensive with said base plate, said filter having a porosity suitablefor filtering whole blood, said filter retaining surgical tissue debrisinside said receptacle on the filter face; a retaining ring meanscoplanarly securing said reservoir base filter to said base plate; anair filter concentrically coextending in said tubular receptacle fromsaid top plate to said base filter, said air filter having a porositysuitable for filtering air and blocking blood flow; an air exit conduitnormally centrally disposed through said top plate, said exit conduitdischarging filtered air from said reservoir; a plurality of blood exitapertures conductively disposed through said base plate, providing forthe flow of filtered blood from said cardiotomy reservoir; and, allaforesaid components physiologically compatible with patient blood. 2.The combination of claim 1 wherein the blood inlet conduit comprises: ablood inlet conduit normally secured through said top plate adjacent thetop plate perimeter and the receptacle wall, said conduit having anozzle having an oriented slot discharge aperture providing a flat inletstream flow tangentially on the inner tubular wall of said receptacle.3. The combination of claim 1 wherein the base plate comprises: aplurality of blood flow relieving passage means disposed in the face ofbase plate adjacent said reservoir base filter.
 4. The combination ofclaim 1 wherein said reservoir base filter comprises: a porousreticulated polyurethane foam having a porosity passing blood elementsranging up to 100 microns diameter, said foam coated with a filmcomposition collapsing blood-air foam.
 5. The combination of claim 1wherein said reservoir base filter comprises: a porous silicone foamhaving a porosity ranging up to 100 micron diameter, said silicone foamcollapsing blood-air foam.
 6. The combination of claim 1 wherein saidreservoir air outlet conduit has a pressure relief valve securedthereon, said valve relieving at a pressure not exceeding 100 mm Hgabove atmospheric.
 7. The combination of Claim 1 wherein said air filtercomprises: a truncated cone shape porous filter having a truncated coneapex centrally disposed adjacent said reservoir base filter and a conebase disposed adjacent said top plate.
 8. The combination of claim 7wherein said truncated cone shape porous filter comprises: a porousreticulated polyurethane foam having a porosity ranging up from 10 poresper lineal inch, said foam coated with an air-blood foam collapsingcomposition.
 9. The combination of claim 7 wherein said truncated coneshape porous filter comprises: a porous silicone foam structure having aporosity ranging up from 10 pores per lineal inch.
 10. In a cardiotomyreservoir whose internal reservoir volume is enclosed by a reservoircase having a case top and case base, the combination comprising: ablood inlet conduit secured through the reservoir wall adjacent saidcase top, said conduit having a nozzle having an oriented dischargeaperture providing a blood inlet stream flow tangentially on the innerwall of said case; a reservoir base filter coextensive with said casebase, said filter having a porosity suitable for filtering whole blood,said filter retaining surgical tissue debris inside said case on thefilter face; a means coplanarly securing said reservoir base filter tosaid case base; an air filter concentrically coextending in saidreservoir case from said case top to said base filter, said air filterhaving a porosity suitable for filtering air and blocking blood flow; anair exit conduit normally centrally disposed through said case top, saidexit conduit discharging filtered air from said reservoir volume; aplurality of blood exit apertures conductively disposed through saidcase base, providing for the flow of filtered blood from said cardiotomyreservoir; and, all aforesaid components physiologically compatible withpatient blood.
 11. The combination of claim 10 wherein the nozzle of theblood inlet conduit has a slot aperture providing a flat oriented bloodinlet flow tangentially on the inner wall of said case.
 12. Thecombination of claim 10 wherein the blood inlet conduit comprises: ablood inlet conduit normally secured through said case top adjacent thecase top perimeter and the case wall, said conduit having a nozzlehaving an oriented slot discharge aperture providing a flat inlet streamflow tangentially on the inner tubular wall of said receptacle.
 13. Thecombination of claim 10 wherein the case base comprises: a plurality ofblood flow relieving passage means disposed in the face of case baseadjacent said reservoir base filter.
 14. The combination of claim 10wherein said reservoir base filter comprises: a porous reticulatedpolyurethane foam having a porosity passing blood elements ranging up to100 microns diameter, said foam coated with a film compositioncollapsing blood-air foam.
 15. The combination of claim 10 wherein saidreservoir base filter comprises: a porous silicone foam having aporosity ranging up to 100 micron diameter, said silicone foamcollapsing blood-air foam.
 16. The combination of claim 10 wherein saidreservoir air outlet conduit has a pressure relief valve securedthereon, said valve relieving at a pressure not exceeding 100 mm Hgabove atmospheric.
 17. The combination of claim 10 wherein said airfilter comprises: a truncated cone shape porous filter having atruncated cone apex centrally disposed adjacent said reservoir basefilter and a cone base disposed adjacent said top plate.
 18. Thecombination of claim 17 wherein said truncated cone shape porous filtercomprises: a porous reticulated polyurethane foam having a porosityranging up from 10 pores per lineal inch, said foam coated with anair-blood foam collapsing composition.
 19. The combination of claim 17wherein said truncated cone shape porous filter comprises: a poroussilicone foam structure having a porosity ranging up from 10 pores perlIneal inch.